I used to wear FM systems in elementary and HS for years. I hated them with a passion. During my HS years, I've lost two detachable pins and I did poke a hole on the middle of screen hole on FM system. I supposed to shell over $600 to replace a slightly damaged FM system, but I was told that school paid for it.
Someone totally destroyed a FM system and other person lost a FM system and had to pay $600 to replace it. Speaking of destroying a FM system, we had no way to know who did it on the last day of school and got away with it (without paying for the damages).